#include <REGX52.H>

void Delay1ms(unsigned int ms)	//@11.0592MHz
{
	unsigned char data i, j;
	while (ms)
	{
		i = 2;
		j = 199;
		do
		{
			while (--j);
		} while (--i);
		ms--;
	}
}

void main(void)
{
	unsigned char LED_Num = 0;
	P2 = ~0x01;
	while (1)
	{
		if (P3_1 == 0)
		{
			Delay1ms(20);
			while(P3_1 == 0);
			Delay1ms(20);
			LED_Num++;
			if (LED_Num >= 8)
			{
				LED_Num = 0;
			}
			P2 = ~(0x01 << LED_Num);
		}
		if (P3_0 == 0)
		{
			Delay1ms(20);
			while(P3_0 == 0);
			Delay1ms(20);
			if (LED_Num == 0)
			{
				LED_Num = 8;
			}
			LED_Num--;
			P2 = ~(0x01 << LED_Num);
		}
	}
}